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File:Laser pointers.jpg This image is near the top. Nice image, probably the most familiar sort of laser for most readers. However what colour is that "indigo" laser? It seems (across several articles and the Commons image) to see-saw between blue and violet/blue-violet, and 445nm and 405nm. Also watch out for caching effects, as there seem to be any number of different versions circulating under the same filename.
IMHO, it's a 405nm violet. But then my eyeballs aren't gamma-corrected, so what do I know?
However we should be describing this as either blue if it's 445 or violet / blue-violet if it's 405nm. 445nm is a blue, not a blue-violet (as currently labelled). Andy Dingley ( talk) 20:00, 22 March 2012 (UTC)
This is way too complicated for the average reader, is there somebody who can describe the operation in a readable summary, maybe one or two paragraphs? I can take a stab at it, but I'm not a laser expert and would probably get yelled at for oversimplifying things. Nerfer ( talk) 21:08, 10 April 2012 (UTC)
My father was a physicist and at one point a friend and colleague of Gordon Gould. He was one of a small group of people who signed a statement to the U.S. Government stating that Gordon Gould was not a communist and was not developing a weapon to use against the U.S. Because Gould's wife was a registered communist his lab equipment and his lab notebooks were confiscated by the U.S. Government. Later, as the family story goes, the lab notebooks were released to Bell Labs, and presumably Townes and Schawlow, who of course later got credit for the invention of the LASER. Growing up, we were aware of the Gordon Gould lawsuit and I remember seeing the newspaper article when he won the lawsuit. The Wikipedia article doesn't mention anything about the confiscation of his lab notebook and their release to Bell Labs. I wonder if anyone has any further information about this, with proper documentation that would allow its inclusion in the Wikipedia article. It's a colorful part of the history. I have no documentation for this. SanJoseRobert ( talk) 01:07, 7 May 2012 (UTC)
I undid some edits, that changed the definition of what a laser is. The issue is whether a "laser" requires an optical resonator. By conventional definition, a laser is a gain medium based on stimulated emission, inside a resonant optical cavity. There are a few cases where the term "laser" is applied to systems that are superradiant, producing optical emission via stimulated emission without feedback from a cavity. Such uses of the term are relatively uncommon, and not unambiguously correct. These uncommon usages should not be given undue weight in the article.
The edits seem to have been partly based on misunderstanding. The editor mentions laser fusion systems like Nova. These systems are not resonator-free lasers as the editor thinks. Rather, these are master oscillator power amplifier systems: a small laser oscillator (consisting of a gain medium inside a cavity) produces the initial laser beam. This beam then passes through a chain of optical amplifiers, e.g. pumped slabs of neodymium-doped glass. It's the oscillator that makes it a laser system. An optical amplifier is not a laser.
The editor also mentions nitrogen lasers, and the article on those does claim that they are commonly built as superluminescent devices, not depending on a resonant cavity. I have added a request for citation on this claim, as I suspect it to be a misunderstanding. An optical cavity does not always imply mirrors as one would normally think about them. For a system with high enough gain, stray reflections off of nearby surfaces (particularly windows or other optical elements along the beam path) are enough to function as a cavity, producing "self-lasing". This is a common problem in high-gain optical amplifiers, sometimes requiring a variety of countermeasures to prevent accidental formation of optical cavities. A system that can emit light on its own via stimulated emission is well into the regime where any reflection back along the length of the device will create true lasing. One would have to work very hard to make a device exhibit superradiant emission rather than self-lasing, by ensuring that reflections back into the cavity are at exceptionally low levels.-- Srleffler ( talk) 02:47, 8 May 2012 (UTC)
Amplified spontaneous emission systems like pumped optical fibers are identified as lasers in standard texts. Perhaps the most common “mirrorless lasers” which use no optical cavity and only a single pass of light through a high-gain medium, include “amplified spontaneous emission” systems such as pumped optical fibers (one class of fiber lasers) see below). Other examples are many types of high gain dye lasers and pulsed excimer lasers. Also high-gain semiconductor laser diodes may be operated so that the mirror reflection at the end of the laser is deliberately spoiled. Molecular lasers such as the nitrogen molecular laser at 337 nm and the hydrogen molecular laser at 120 nm, especially when pumped by fast transverse electric discharges or electron beams, operate without an optical resonator. Mirrorless lasing occurs in infrared lines with high gain, such as the 3.39 micron line in He-Ne lasers, and the 3.51 micron mode in He-Xe lasers. The many natural high power lasers and masers in astronomical sources also operate without mirrors. See Lasers. pp. 550-551 (mirrorless lasers section) Anthony E. Siegman. Stanford University. ISBN 978-0-935702-11-8, 1986. [1] An astronomical source example is MWC 349. Finally, X-ray lasers of various types (nuclear weapon pumped lasers, and free electron lasers) operating in frequency regions in which mirroring is impossible, require no optical cavity. Finally, those nuclear fusion lasers need a master oscillator only for pulse shaping. If you charged up all those flash lamps and fired them without an input signal, you'd still get a lot of laser power out the other end-- it just wouldn't be coordinated. But you still wouldn't want to stand in front of it (or have your pinkie in it, or whatever). S B H arris 03:42, 8 May 2012 (UTC)
I reworked the Design section as a result of the discussion above, relying on Siegman's definition that "optical feedback" is required, and moving discussion of optical resonators down a bit in the section and describing it as common, rather than a mandatory element. I also reworked the comment about an amplifier in a cavity being a laser by saying instead that it is a laser oscillator. I don't think anyone here will dispute that putting an amplifier in a cavity makes a laser oscillator (and Siegman supports that statement). The disagreement is just over whether the amplifier is a "laser" in its own right, which the text no longer addresses one way or the other.
A side note: the edit comment on the request for citation regarding amplifiers read "[A]n optical amplifier that produces coherent light by stimulated emission, is not a laser until you add an optical cavity? Give the cite." While I take the point seriously, as phrased the question seems to include a misunderstanding. An optical amplifier does not produce coherent light by itself. It might emit amplified spontaneous emission ("superluminescence"), but that is not coherent. An amplifier can of course produce coherent output by amplifying a coherent input beam. If it produces coherent light on its own, then it is a laser, but except for rare and odd cases, this requires some kind of optical feedback. -- Srleffler ( talk) 03:02, 10 May 2012 (UTC)
A gain medium pumped into being able to produce amplification is like a fissile mass that is supercritical. All it needs is a neutron, and there's always a neutron. Of course, amplifiers with no cavities are more apt to produce pulses, and these pulses are not as good as if they were managed (same with nuclear weapons, which give much better explosions if radiated with neutrons at just the right time). In a few cases, the gain is so high in the medium and the pumping input is so large and effective, that a CW is emitted. Astronomical laser sources seem to be in this category. In most cases, an amplifier set up to amplify with no input is not as efficient or powerful at producing laser radiation, but it will produce laser radiation and that makes it a laser. I would be willing to bet this is true of Nova as well (how could it not be?).
I would be willing to bet it's true of simple helium-neon laser, so long as the tube is long enough that it could indeed BE used as a laser amplifier. See the discussion at the end of chapter 4 on lasing theshholds [2] It takes about 30 cm of plasma in an He-Ne laser before you get first pass-amplification of light (gains exceed loses in the the pumped medium). You can make a He-Ne laser shorter than this, but it wouldn't function as a amplifier because it is too lossy to do so. But with a longer tube, capable of one-pass amplication, now you really don't need mirrors to see some laser light. You'd get far, far weaker laser light with a mirrorless amplifier. But not NONE. S B H arris 19:50, 11 May 2012 (UTC)
If the article says this, then it will agree with the texts, and I'll be happy. And we can then explain nuclear X-ray lasers without too much difficulty, and the operation of many "free electron lasers" (FELs). Although for the terms of stimulated emission, in FELs I suppose one has to interpret it rather loosely to include all processes that tend to bunch electrons into groups that radiate together, and not just quantum processes like fluorescence. (Some of the same processes as in FELs happen in some traveling wave tubes, but with non-relativistic electrons). However, interestingly, FELs are often started off with "noise" rather than a seed signal, and they then progress from there to lasing with no feedback. Which is good, since some FELs must operate in the UV or X-ray where there is no way to have feedback. See self-amplified stimulated emission. How are you going to explain "laser emission" from such a beast, using the arguments that you insist on using? S B H arris 03:42, 16 May 2012 (UTC)
The section on laser uses is very cursory. I propose expanding it somewhat to give a better overview of laser applications. We could do it by regrouping and adding a short paragraph on each of the following topics:
What do you think of these broad categories?— Preceding unsigned comment added by Davisonkirby ( talk • contribs) 12:50, 3 July 2012
Here it says that lasers have not been successfully developed as weapons. However the article MIRACL describes just such a weapon. So why is this not mentioned here? — Preceding unsigned comment added by Samsite ( talk • contribs) 12:39, 25 September 2012 (UTC)
Croatian writer Giancarlo Kravar: German company Rheinmetall AG, which manufactures weapons and auto parts, introduced a system of laser weapons that can knock down two unmanned spacecraft at a distance of over 1.5 km, the BBC reported Tuesday. The demonstration of laser weapons, unmanned aircraft that are assembled at a speed of 50 meters per second, were ruined when they were in the programmed sector of fire. The company tested the system in various weather conditions, including snow, sun and rain, and the weapon system uses radar to roughly target drones, while for fine tracking targets include optical system. The company plans to produce mobile laser weapon system and integrate it into automatic gun. 78.3.219.240 ( talk) 17:58, 9 January 2013 (UTC)
The short section that discusses lasers as a hobby is mostly useless because it doesn't say what hobbyists do with the laser. Telescope hobbyists build telescopes to look at the stars. HAM radio hobbyists use their devices to communicate. What exactly do laser hobbyists do with the lasers? The article should say. Simply saying some people play with lasers is pointless. Every article in Wikipedia could have a similar section saying that some people play with the article's subject. Either erase this section or give it some details to make it useful. Is there s laser hobbyist magazine? Are the laser hobbyist conferences? 129.63.129.196 ( talk) 18:34, 31 January 2013 (UTC)
See spelling of disc. For optical devices, the spelling is disc. If this spelling edit war continues, then, I will slap the British English tag on this talk page, and I am in Washington, DC. Stop the edit war and use the agreed spelling. Robert McClenon ( talk) 01:33, 2 July 2013 (UTC)
Text copied from Ruby laser:
LASER is an acronym which should always be capitalized. — Preceding unsigned comment added by N0ty ( talk • contribs) 12:44, 6 September 2013 (UTC)
Whether an acronym (the meaning of which I prefer to limit to any abbreviation that is pronounceable) is capitalized or not is mostly (but not always) an easy determination and merely has to do with whether the acronym refers to an organization. So "NATO" is all caps because it is the acronymic abbreviation for "North Atlantic Treaty Organization." The word "laser" is entirely lower case (except, obviously, if it begins a sentence) because it refers to the phrase "light amplification by stimulated emission of radiation," as it states in the article under heading 1.1 "Terminology." Military organizations idiosyncratically use all caps in their acronyms, such as "CDRUSPACOM" (Commander, U.S. Pacific Command) [which prior to 2002 was "CINCPAC" (Commander-in-Chief, U.S. Pacific Command), considerably more pronounceable but changed probably because of possible confusion with the real Commander-in-Chief, the President of the US], but any further discussion of this matter belongs elsewhere in Wikipedia.
In my opinion it is also incorrect, and possibly confusing, to capitalize the initial letters of the words of this phrase in the introductory paragraph of this article: "...The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation.[1]...." The reason it is presented this way, I suspect, is an artifact caused by the writer's having copied the phrase as it is presented in the reference given, reference [1], in which the phrase is shown this way. But the only reason it is shown this way is surely merely because the phrase is part of the title of an article: "Gould, R. Gordon (1959). 'The LASER, Light Amplification by Stimulated Emission of Radiation'. In Franken, P.A. and Sands, R.H. (Eds.). The Ann Arbor Conference on Optical Pumping, the University of Michigan, 15 June through 18 June 1959. p. 128. OCLC 02460155." I, therefore, urge the writer to change to lower case those words of this phrase in the introductory paragraph now beginning with capital letters. Wikifan2744 ( talk) 07:51, 11 December 2013 (UTC)
I'm happy to see that the laser has been denoted as a significant technology, and I'm willing to invest effort in improving the article, but I'd like other editors thoughts on what key changes would help the article.
I feel the overall tone, and certainly the introduction, is tilted towards what makes the laser scientifically interesting rather than what makes it a valuable technology. I feel shifting that balance by providing a greater emphasis on applications and people's daily encounters with lasers would be beneficial.
Several of the current section feel like they would be better served by being distinct articles that were not trying to serve as broad an audience. Could the Laser Physics section be largely moved into laser science? How about limiting the discussion of laser types to one paragraph here and creating a separate article for anything more detailed than that?
To reconsider the overall structure of the article, I went searching for analogous topics that have an article with a higher rating. The three I found were steel, camera and telescope. I'm going to review these as potential guides. Do you have thoughts on other analogous articles?
Thanks for any thoughts and suggestions you can offer. I hope we can work together to raise the quality of this article. ronningt ( talk) 13:14, 8 December 2013 (UTC)
"It fundamentally changes the way we fight," said Capt. Mike Ziv, program manager for directed energy and electric weapon systems for the Naval Sea Systems Command.
"The Navy plans to deploy its first laser on a ship later this year, and it intends to test an electromagnetic rail gun prototype aboard a vessel within two years." — FYI, Charles Edwin Shipp ( talk) 15:23, 18 February 2014 (UTC) PS: There are some nice pictures.
More pictures, same AP story, February 17, 2014. FYI, Charles Edwin Shipp ( talk) 16:15, 18 February 2014 (UTC)
Really? 80.2.87.59 ( talk) 21:35, 19 March 2014 (UTC)
I am coming to laser optics from imaging with incoherent light and I'm trying to clarify a few things. First, I was surprised to learn that laser diodes spray light out over a wide angle—that they need a lens to produce a beam. This raises the question: is it their coherence that makes a laser diode well-suited to producing a beam or is it something about the area and angle over which light is emitted?
Specifically:
Thanks. —Ben FrantzDale ( talk) 03:16, 3 April 2014 (UTC)
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Please edit "A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation." so that when hovering above the word "laser" the full meaning should appear. This would be good for people viewing as the word is already bold and it provides an easier way to show the meaning of "laser" The following code can be used (the first is the original followed by the edited code: Original: A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Edited: A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. RahulSanthosh ( talk) 08:55, 19 May 2014 (UTC)
{{
edit semi-protected}}
template. I believe there is a current consensus in place against hovering definitions of words. I also believe there "may" be a userscript or gadget that will allow you to see some words like that. — {{U|
Technical 13}} (
t •
e •
c) 12:25, 19 May 2014 (UTC)This
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This article omits one of the most prominent and impactful applications of the laser - optical fiber communications.
At a BARE minimum, the 2nd paragraph should be edited from its current form:
Lasers have many important applications. They are used in common consumer devices such as optical disk drives, laser printers, and barcode scanners. They are used in medicine for laser surgery and various skin treatments, and in industry for cutting and welding materials. They are used in military and law enforcement devices for marking targets and measuring range and speed. Laser lighting displays use laser light as an entertainment medium. NASA has been experimenting with lasers for the purpose of transmitting data from space.[3] Lasers also have many important applications in scientific research.
to the following:
Lasers have many important applications. They are used in common consumer devices such as optical disk drives, laser printers, and barcode scanners. They are used in optical fiber communications to enable the internet. They are used in medicine for laser surgery and various skin treatments, and in industry for cutting and welding materials. They are used in military and law enforcement devices for marking targets and measuring range and speed. Laser lighting displays use laser light as an entertainment medium. NASA has been experimenting with lasers for the purpose of transmitting data from space.[3] Lasers also have many important applications in scientific research.
Optoeng ( talk) 21:50, 12 July 2014 (UTC)
Done Wow, yes. I'm not sure how we missed that. Thanks for pointing it out.-- Srleffler ( talk) 04:44, 14 July 2014 (UTC)
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I was taught in physics that it meant "linear amplification of spectral emission radiation" which is far more correct. When one examines the mode of operation this def'n is much more accurate. The gas is excited by a current causing an electron to raise to a higher orbital. When the field is collapsed the excited electrons all fall back simultaneously, giving off a photon at a characteristic wavelength, or spectrum. This is called "spectral emission radiation". The nature of the tube and window cause the linear amplification. Thank you 122.109.51.141 ( talk) 10:07, 23 July 2014 (UTC)
LASER is an acronym, why is the article name laser? 202.123.130.53 ( talk) 12:03, 25 August 2014 (UTC)
In the Semiconductor lasers section it's written:
Here is a good overview of commercially available wavelength that can be used as a reference.
This part
can be removed. These wavelength and particular diodes are listed in the reference above.
In general I would distinguish between laser diodes and diode lasers. This section is about laser diodes. External-cavity semiconductor lasers are diode lasers, i.e. systems. I would open a seperate section for diode lasers and write an article about diode lasers, unfortunately English is not my mother tongue. But is somebody know German, the respective article is here — Preceding unsigned comment added by 141.89.75.210 ( talk) 17:05, 26 September 2014 (UTC)
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85.189.149.201 ( talk) 08:44, 12 January 2015 (UTC) lasers are a bright light which can blind people and are banned in the uk and many other countries.
The usage and primary topic of laserlight is under discussion, see talk:LaserLight -- 65.94.43.89 ( talk) 10:16, 29 April 2015 (UTC)
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Please change
{{redirect|Laser light|the song|LaserLight}}
to
{{redirect|Laser light|the song|LaserLight|laser light show|laser lighting display}}
-- 65.94.43.89 ( talk) 10:22, 29 April 2015 (UTC)
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Experimentation in ultra violet laser technology has demonstrated the short burst potential of a laser can be reduced to attosecond length bursts.
Shirtbrigade ( talk) 12:43, 8 June 2015 (UTC)
Not done: as you have not cited reliable sources to back up your request, without which no information should be added to, or changed in, any article. - Arjayay ( talk) 13:01, 8 June 2015 (UTC)
Around the time of its invention, the laser was famously labelled 'a solution in need of a problem', but now it has penetrated so many aspects of industry, science and our daily lives that the number of applications are countless.
My emphasis. With a better source, that should become part of the history section. 85.178.192.101 ( talk) 13:16, 13 August 2015 (UTC)
I read something about a "monomode laser". Could someone define that term, please? Equinox ( talk) 13:46, 15 January 2016 (UTC)
See http://www.eng.umd.edu/html/ihof/inductees/weber.html for a summary of Joseph Weber's contributions to the development of the maser.
Added. EAWH ( talk) 02:28, 16 March 2016 (UTC)
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The title of the page is currently 'Laser' which is incorrect grammar for the topic presented. I request for a change of all words in/on page '(Laser -or- laser)' to be changed to 'LASER' due to the correct term being 'Light Amplification by Stimulated Emission of Radiation' Which is stated in the page on line 4 (line 3 if not including blank line) or the second sentence in the first paragraph. WTLM2013 ( talk) 14:20, 11 May 2016 (UTC)
Not done as policy mentioned above, and because, although derived from "Light Amplification by the Stimulated Emission of Radiation", as an acronym, laser is now a stand alone word in its own right.
You can find previous discussions about this further up on this page, and in the archives linked at the top of this page - the consensus is to stick with laser -
Arjayay (
talk) 15:47, 11 May 2016 (UTC)
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Perhaps someone could add to the first section that some lasers emit only one color of light because different colors will refract differently, and having a single wavelength keeps the beam narrow.
50.5.106.186 ( talk) 15:19, 11 August 2016 (UTC)
Not done Not a "complete and specific description of the request." Meters ( talk) 17:14, 11 August 2016 (UTC)
I've set "answered" to no because while the first section states that lasers emit a narrow spectrum, it is not clear to a person of mediocre intelligence that it allows the beam to stay narrow despite refraction.— Preceding unsigned comment added by 50.5.105.58 ( talk • contribs) 16:49, 9 October 2016 (UTC)
From the opening of the Gain medium and cavity subsection:
"Excited into an excited state?" Might as well say it was "purpled into a purpled state", or "frazzlerazzed into a frazzlerazzed state". The repetition is awkward, and fails to explain the meaning of "excited" in context.
Suggest replacing the sentence with "The gain medium is excited by an external source of energy", and then explaining what that means, or perhaps "The gain medium is placed in an excited state by an external energy source", again followed by an explanation of what "excited" means in this context.
Would have fixed it myself, but editing appears to be broken for this article. — Preceding unsigned comment added by 74.95.43.249 ( talk) 19:37, 27 October 2016 (UTC)
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The most important and biggest problem with building the first laser (and all and any lasers) was (is) that a two level system described in the Laser physics/Stimulated emission section could not amplify light because it can not attain population inversion; population inversion is a necessary contidion for a laser. Instead, a three level system needs to be used. The need for a three level system is crucial for understanding how a laser actually works and nowhere did I see it explained in the article. Someone who is better at writing/explaining than I am should add that in there. Details can be found, for example, in Svelto, Orazio (1998). Principles of Lasers. 4th ed. Trans. David Hanna. Springer. ISBN 0-306-45748-2. in the first chapter and in the chapter 1.3 especially about the necessity for a three level system. This book is cited as as a source in the article already. 93.142.7.8 ( talk) 10:57, 10 August 2017 (UTC)
I disagree with this edit and have partly reverted it. I would like to revert it completely, but am opening the issue up for discussion first.
The history is too important not to mention key points in the lede. The fact that Maiman was the first to build a working laser is not in dispute, and should be mentioned.
Gould is rightly considered the "inventor" of the laser, but only in the very narrow sense used in patent law, and that claim is tainted by the fact that he was (unjustly, in my opinion) denied the patent on the laser itself by the patent office. Gould does not deserve scientific credit for the theory of the laser, because he did not publish his work. Unlike the patent office, scientists credit the first to publish a discovery, not the first to think of the idea. The early scientific work on lasers is largely based on Schawlow and Townes' work, and they are conventionally credited with having originated the theory. I don't think there is any dispute that it is their theoretical work that led to Maiman's success in building the first laser, and their role is important enough that it should be mentioned in the lede.-- Srleffler ( talk) 07:48, 10 February 2018 (UTC)
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The term under consideration: In 2017, researchers from the Physikalisch-Technische Bundesanstalt (PTB), together with US researchers from JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, established a new world record by developing a laser with a linewidth of only 10 millihertz.[29]
In the cited article the authors describe that they have not used a gas laser, please see in [29]: "Commercial Er-doped distributed feedback (DFB) fiber lasers at 1542 nm (ν0=194.4THz) are frequency stabilized to the cavities using the Pound-Drever-Hall (PDH) method. Fiber-coupled acousto-optic modulators (AOMs) are used for the fast servo allowing locking bandwidths of around 150 kHz."
Recommended solution: Change the thematic classification to "Fiber lasers", which is now at "Gas Lasers".
Further information to the original term: Date: 10:32, 3 July 2017 Contributor: Bilingual2000 Topic: Gas lasers - added data and ref about the sharpest laser in the world with a linewidth of only 10 miliHertz) 141.24.58.195 ( talk) 13:09, 17 March 2018 (UTC)
Not done for now: I don't see the statement about Er-doped DFB lasers anywhere in reference 29. Reference 29 is The sharpest laser in the world. As far as I can see, it does not identify what the gain medium of the laser is. Where did you see that?-- Srleffler ( talk) 16:17, 18 March 2018 (UTC)
Partly done: I see now: your quote was from the Phys. Rev. Lett. paper, which is cited in reference 29. You are right—this is not a gas laser. I moved the paragraph to "Recent Innovations" rather than to "Fiber Lasers", though.-- Srleffler ( talk) 16:35, 18 March 2018 (UTC)
"Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond."
This formulation tends to let the reader to think that one needs a narrow spectrum to produce an ultrashort laser beam. It is actually the opposite due to Heisenberg uncertainty principle. To produce an ultrashort pulse (typically in the femtosecond range) one need a broad spectrum — Preceding unsigned comment added by MatthieuVe ( talk • contribs)
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Towards end of article, before sources section.
Lasers can be a hazard to both civil and miliatary aviation
'military' is spelled incorrectly. Tillmechanic ( talk) 17:13, 16 May 2019 (UTC)
@ Srleffler: per Wikipedia:Manual_of_Style/Pronunciation: For English words and names, pronunciation should normally be omitted for common words or when obvious from the spelling; use it only for foreign loanwords (coup d'etat), names with counterintuitive pronunciation (Leicester, Ralph Fiennes), or very unusual words (synecdoche)."
The pronunciation of laser is famously counterintuitive, and therefore should be included.
Onceinawhile ( talk) 19:10, 7 June 2020 (UTC)
I think that every article on Wikipedia should be written with encylopidic language. It'll be better if "LASER" redirected to "Light Amplification by Stimulated Emission of Radiation", not vice-versa, how it is now. BonsMans1 ( talk) 13:41, 26 October 2020 (UTC)
is laser light a tautology— Preceding unsigned comment added by 2601:2c3:4201:d70:5922:ac02:c737:d141 ( talk • contribs) 17:00, 28 November 2020 (UTC)
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Please change "1.3 PW (1.3×1015 W) – world's most powerful laser as of 1998, located at the Lawrence Livermore Laboratory[95]" to "10 PW - world's most powerful laser as of 2019, located at the ELI-NP facility in Măgurele, Ilfov, Romania. [1] [2]"
Gabi 2003RO ( talk) 16:29, 22 March 2021 (UTC)
References
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Please let me correct errors made by mindless editors. Phillotus ( talk) 23:18, 18 October 2021 (UTC)
I was surprised to see that the History section began with Einstein, making no mention of the original paper by Satyendra Nath Bose. Einstein's papers were founded in Bose's work, and in fact Einstein was instrumental in getting Bose's original paper published. Bose's paper was on the statistics of bosons, which was written at a time when the study of quantum statistics had developed a theory for fermions but not yet for bosons. Hs work was so important that bosons were named for him. Bose deserves mention. I'm adding a reference to his work.— MiguelMunoz ( talk) 08:30, 1 December 2021 (UTC)
Also, the article cites a 1917 paper by Einstein, On the Quantum Theory of Radiation from 1917, but I don't think that's right. The article on Bose claims his foundational paper was written in 1924, which was published with Einstein's help, in the same German journal as the 1917 paper. As I understand it, Bose's 1924 paper was the foundation of Boson statistics, which control the behavior of lasers. I'm going to look into this further. — MiguelMunoz ( talk) 08:54, 1 December 2021 (UTC)
The "Quantum vs. classical emission processes" section cites no sources. Please can someone add some helpful and trustworthy sources? Or at least add a "citations required" tag? Thanks. — Preceding unsigned comment added by 138.38.97.65 ( talk) 08:56, 6 February 2022 (UTC)
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I believe that a changes should be made in the section "Types and operating principles", subsection "Exotic media". Specificaly in the last paragraph, there is a description of a laser which uses living cells as an active medium. It is stated that "the mirrors were only 20 millionth of a meter apart". Such sensationalism has no place in a scientific article and it should definitely not be a part of Wikipedia. More natural would be to simply say 20 micrometers/microns. Also the author is using quotation marks relating terms like "gain medium" and "laser cavity". This is obsolete, these are standard terms that don't require quotation marks.
Sedlaon ( talk) 07:06, 11 April 2022 (UTC)
Done-- Srleffler ( talk) 03:21, 13 April 2022 (UTC)
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Dominics52 ( talk) 18:16, 15 April 2022 (UTC) I wanna see the sources of lasers
Can someone provide a better graph of the spectrum of a laser. The current one ( HeNe) is not very good for the following reasons: 1) The electronic background of the spectrometer is not subtracted so all the values that should be zero are currently quite wrongly shown, 2) the actual spectral distribution of the line is not shown - as the spectral width shown is clearly the band-pass function of the spectrometer and not the laser line-width. Thorseth ( talk) 10:00, 15 August 2022 (UTC)
Can someone please resolve the fact that every spelling of LASER in this article is incorrect? There's even a line stating LASER is an acronym and explains what it means but spells it in lower case. At least you didn't spell it with a Z. 92.1.183.81 ( talk) 19:50, 1 September 2022 (UTC)
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The first laser, it was called a maser, was made in 1953 – 1954 by N.G. Basov and A.M. Prokhorov. In 1964, Basov and Prokhorov received the Nobel Prize in Physics.
https://ru.m.wikipedia.org/wiki/%D0%91%D0%B0%D1%81%D0%BE%D0%B2,_%D0%9D%D0%B8%D0%BA%D0%BE%D0%BB%D0%B0%D0%B9_%D0%93%D0%B5%D0%BD%D0%BD%D0%B0%D0%B4%D0%B8%D0%B5%D0%B2%D0%B8%D1%87 2A00:1FA1:4231:F126:2C9:BC40:D9D5:252D ( talk) 08:35, 2 September 2022 (UTC)
As the article states, this is an acronym. It is spelled "LASER". 79.106.209.51 ( talk) 23:43, 29 December 2022 (UTC)
Seems odd, and strange, to me that the verbage of the article calls lasers “they” as if it’s a living being.
Didn’t find much info on laser light shows that aren’t raves, either.
2600:8801:0:2B10:1C4B:8BDE:2599:1884 ( talk) 14:26, 17 January 2023 (UTC)
The history section claims that Javan was the first to propose the semiconductor laser. Not only had others proposed it before him in some capacity (Jun-ichi Nishizawa, for example, who is actually mentioned earlier in that same section), but this claim is not cited, or flagged as needing citation. I have looked extensively for a source to back up this claim, but can find nothing. This seems to be, at best, original research, and at worst, a fabrication. This error should probably be amended.
(G!d bless Ali Javan by the way, huge inspiration to me) ProteinFromTheSea ( talk) 23:58, 30 May 2023 (UTC)
As expressed in the notes left to some (laser) physics-specialised users, I am planning on making the level-3 vital article "Laser" a GA. Two persons responded to these notes —one directly and one indirectly by editing the article to some extent—, and I think now is the time for me to start intervening more energetically.
Having taken the six GA criteria into consideration, I list my intentions/suggestions below:
1.a. & 1.b. Language style homogenisation; I'm planning on reading the whole article and making sure the text is technically and stylistically consistent. At the same time, I'll ensure Manual of Style compliance.
2. a. I know it shan't be easy, but I shall try to turn all citations to
Harvard referencing, for I find it more easy to handle, more "tidy" (cancelled, see below).
2.b. & 2.c. I will try to find citations for all text requiring substantiation.
2.d. Using Earwig's Copyvio etc, I'll check for possible copyright violations.
3. I do not think much vitally important information is missing from the article, but if I find any omissions, I'll fix them.
4. The article is probably neutral, but I'll make it more so, if possible.
6. Some important pictures are missing; for example, a photo of the late Mr. Maiman ought to be included.
Let's get to work, then! Whoever willing to help is invited to do so.
P.S. Bear in mind that some of my extensive edits might significantly change the article's appearance and structure over a short period of time, so it would be more convenient if you informed me of any intended extensive change beforehand, here, at the article's talk page. L'Orfeo Son io 11:40, 15 October 2023 (UTC)
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File:Laser pointers.jpg This image is near the top. Nice image, probably the most familiar sort of laser for most readers. However what colour is that "indigo" laser? It seems (across several articles and the Commons image) to see-saw between blue and violet/blue-violet, and 445nm and 405nm. Also watch out for caching effects, as there seem to be any number of different versions circulating under the same filename.
IMHO, it's a 405nm violet. But then my eyeballs aren't gamma-corrected, so what do I know?
However we should be describing this as either blue if it's 445 or violet / blue-violet if it's 405nm. 445nm is a blue, not a blue-violet (as currently labelled). Andy Dingley ( talk) 20:00, 22 March 2012 (UTC)
This is way too complicated for the average reader, is there somebody who can describe the operation in a readable summary, maybe one or two paragraphs? I can take a stab at it, but I'm not a laser expert and would probably get yelled at for oversimplifying things. Nerfer ( talk) 21:08, 10 April 2012 (UTC)
My father was a physicist and at one point a friend and colleague of Gordon Gould. He was one of a small group of people who signed a statement to the U.S. Government stating that Gordon Gould was not a communist and was not developing a weapon to use against the U.S. Because Gould's wife was a registered communist his lab equipment and his lab notebooks were confiscated by the U.S. Government. Later, as the family story goes, the lab notebooks were released to Bell Labs, and presumably Townes and Schawlow, who of course later got credit for the invention of the LASER. Growing up, we were aware of the Gordon Gould lawsuit and I remember seeing the newspaper article when he won the lawsuit. The Wikipedia article doesn't mention anything about the confiscation of his lab notebook and their release to Bell Labs. I wonder if anyone has any further information about this, with proper documentation that would allow its inclusion in the Wikipedia article. It's a colorful part of the history. I have no documentation for this. SanJoseRobert ( talk) 01:07, 7 May 2012 (UTC)
I undid some edits, that changed the definition of what a laser is. The issue is whether a "laser" requires an optical resonator. By conventional definition, a laser is a gain medium based on stimulated emission, inside a resonant optical cavity. There are a few cases where the term "laser" is applied to systems that are superradiant, producing optical emission via stimulated emission without feedback from a cavity. Such uses of the term are relatively uncommon, and not unambiguously correct. These uncommon usages should not be given undue weight in the article.
The edits seem to have been partly based on misunderstanding. The editor mentions laser fusion systems like Nova. These systems are not resonator-free lasers as the editor thinks. Rather, these are master oscillator power amplifier systems: a small laser oscillator (consisting of a gain medium inside a cavity) produces the initial laser beam. This beam then passes through a chain of optical amplifiers, e.g. pumped slabs of neodymium-doped glass. It's the oscillator that makes it a laser system. An optical amplifier is not a laser.
The editor also mentions nitrogen lasers, and the article on those does claim that they are commonly built as superluminescent devices, not depending on a resonant cavity. I have added a request for citation on this claim, as I suspect it to be a misunderstanding. An optical cavity does not always imply mirrors as one would normally think about them. For a system with high enough gain, stray reflections off of nearby surfaces (particularly windows or other optical elements along the beam path) are enough to function as a cavity, producing "self-lasing". This is a common problem in high-gain optical amplifiers, sometimes requiring a variety of countermeasures to prevent accidental formation of optical cavities. A system that can emit light on its own via stimulated emission is well into the regime where any reflection back along the length of the device will create true lasing. One would have to work very hard to make a device exhibit superradiant emission rather than self-lasing, by ensuring that reflections back into the cavity are at exceptionally low levels.-- Srleffler ( talk) 02:47, 8 May 2012 (UTC)
Amplified spontaneous emission systems like pumped optical fibers are identified as lasers in standard texts. Perhaps the most common “mirrorless lasers” which use no optical cavity and only a single pass of light through a high-gain medium, include “amplified spontaneous emission” systems such as pumped optical fibers (one class of fiber lasers) see below). Other examples are many types of high gain dye lasers and pulsed excimer lasers. Also high-gain semiconductor laser diodes may be operated so that the mirror reflection at the end of the laser is deliberately spoiled. Molecular lasers such as the nitrogen molecular laser at 337 nm and the hydrogen molecular laser at 120 nm, especially when pumped by fast transverse electric discharges or electron beams, operate without an optical resonator. Mirrorless lasing occurs in infrared lines with high gain, such as the 3.39 micron line in He-Ne lasers, and the 3.51 micron mode in He-Xe lasers. The many natural high power lasers and masers in astronomical sources also operate without mirrors. See Lasers. pp. 550-551 (mirrorless lasers section) Anthony E. Siegman. Stanford University. ISBN 978-0-935702-11-8, 1986. [1] An astronomical source example is MWC 349. Finally, X-ray lasers of various types (nuclear weapon pumped lasers, and free electron lasers) operating in frequency regions in which mirroring is impossible, require no optical cavity. Finally, those nuclear fusion lasers need a master oscillator only for pulse shaping. If you charged up all those flash lamps and fired them without an input signal, you'd still get a lot of laser power out the other end-- it just wouldn't be coordinated. But you still wouldn't want to stand in front of it (or have your pinkie in it, or whatever). S B H arris 03:42, 8 May 2012 (UTC)
I reworked the Design section as a result of the discussion above, relying on Siegman's definition that "optical feedback" is required, and moving discussion of optical resonators down a bit in the section and describing it as common, rather than a mandatory element. I also reworked the comment about an amplifier in a cavity being a laser by saying instead that it is a laser oscillator. I don't think anyone here will dispute that putting an amplifier in a cavity makes a laser oscillator (and Siegman supports that statement). The disagreement is just over whether the amplifier is a "laser" in its own right, which the text no longer addresses one way or the other.
A side note: the edit comment on the request for citation regarding amplifiers read "[A]n optical amplifier that produces coherent light by stimulated emission, is not a laser until you add an optical cavity? Give the cite." While I take the point seriously, as phrased the question seems to include a misunderstanding. An optical amplifier does not produce coherent light by itself. It might emit amplified spontaneous emission ("superluminescence"), but that is not coherent. An amplifier can of course produce coherent output by amplifying a coherent input beam. If it produces coherent light on its own, then it is a laser, but except for rare and odd cases, this requires some kind of optical feedback. -- Srleffler ( talk) 03:02, 10 May 2012 (UTC)
A gain medium pumped into being able to produce amplification is like a fissile mass that is supercritical. All it needs is a neutron, and there's always a neutron. Of course, amplifiers with no cavities are more apt to produce pulses, and these pulses are not as good as if they were managed (same with nuclear weapons, which give much better explosions if radiated with neutrons at just the right time). In a few cases, the gain is so high in the medium and the pumping input is so large and effective, that a CW is emitted. Astronomical laser sources seem to be in this category. In most cases, an amplifier set up to amplify with no input is not as efficient or powerful at producing laser radiation, but it will produce laser radiation and that makes it a laser. I would be willing to bet this is true of Nova as well (how could it not be?).
I would be willing to bet it's true of simple helium-neon laser, so long as the tube is long enough that it could indeed BE used as a laser amplifier. See the discussion at the end of chapter 4 on lasing theshholds [2] It takes about 30 cm of plasma in an He-Ne laser before you get first pass-amplification of light (gains exceed loses in the the pumped medium). You can make a He-Ne laser shorter than this, but it wouldn't function as a amplifier because it is too lossy to do so. But with a longer tube, capable of one-pass amplication, now you really don't need mirrors to see some laser light. You'd get far, far weaker laser light with a mirrorless amplifier. But not NONE. S B H arris 19:50, 11 May 2012 (UTC)
If the article says this, then it will agree with the texts, and I'll be happy. And we can then explain nuclear X-ray lasers without too much difficulty, and the operation of many "free electron lasers" (FELs). Although for the terms of stimulated emission, in FELs I suppose one has to interpret it rather loosely to include all processes that tend to bunch electrons into groups that radiate together, and not just quantum processes like fluorescence. (Some of the same processes as in FELs happen in some traveling wave tubes, but with non-relativistic electrons). However, interestingly, FELs are often started off with "noise" rather than a seed signal, and they then progress from there to lasing with no feedback. Which is good, since some FELs must operate in the UV or X-ray where there is no way to have feedback. See self-amplified stimulated emission. How are you going to explain "laser emission" from such a beast, using the arguments that you insist on using? S B H arris 03:42, 16 May 2012 (UTC)
The section on laser uses is very cursory. I propose expanding it somewhat to give a better overview of laser applications. We could do it by regrouping and adding a short paragraph on each of the following topics:
What do you think of these broad categories?— Preceding unsigned comment added by Davisonkirby ( talk • contribs) 12:50, 3 July 2012
Here it says that lasers have not been successfully developed as weapons. However the article MIRACL describes just such a weapon. So why is this not mentioned here? — Preceding unsigned comment added by Samsite ( talk • contribs) 12:39, 25 September 2012 (UTC)
Croatian writer Giancarlo Kravar: German company Rheinmetall AG, which manufactures weapons and auto parts, introduced a system of laser weapons that can knock down two unmanned spacecraft at a distance of over 1.5 km, the BBC reported Tuesday. The demonstration of laser weapons, unmanned aircraft that are assembled at a speed of 50 meters per second, were ruined when they were in the programmed sector of fire. The company tested the system in various weather conditions, including snow, sun and rain, and the weapon system uses radar to roughly target drones, while for fine tracking targets include optical system. The company plans to produce mobile laser weapon system and integrate it into automatic gun. 78.3.219.240 ( talk) 17:58, 9 January 2013 (UTC)
The short section that discusses lasers as a hobby is mostly useless because it doesn't say what hobbyists do with the laser. Telescope hobbyists build telescopes to look at the stars. HAM radio hobbyists use their devices to communicate. What exactly do laser hobbyists do with the lasers? The article should say. Simply saying some people play with lasers is pointless. Every article in Wikipedia could have a similar section saying that some people play with the article's subject. Either erase this section or give it some details to make it useful. Is there s laser hobbyist magazine? Are the laser hobbyist conferences? 129.63.129.196 ( talk) 18:34, 31 January 2013 (UTC)
See spelling of disc. For optical devices, the spelling is disc. If this spelling edit war continues, then, I will slap the British English tag on this talk page, and I am in Washington, DC. Stop the edit war and use the agreed spelling. Robert McClenon ( talk) 01:33, 2 July 2013 (UTC)
Text copied from Ruby laser:
LASER is an acronym which should always be capitalized. — Preceding unsigned comment added by N0ty ( talk • contribs) 12:44, 6 September 2013 (UTC)
Whether an acronym (the meaning of which I prefer to limit to any abbreviation that is pronounceable) is capitalized or not is mostly (but not always) an easy determination and merely has to do with whether the acronym refers to an organization. So "NATO" is all caps because it is the acronymic abbreviation for "North Atlantic Treaty Organization." The word "laser" is entirely lower case (except, obviously, if it begins a sentence) because it refers to the phrase "light amplification by stimulated emission of radiation," as it states in the article under heading 1.1 "Terminology." Military organizations idiosyncratically use all caps in their acronyms, such as "CDRUSPACOM" (Commander, U.S. Pacific Command) [which prior to 2002 was "CINCPAC" (Commander-in-Chief, U.S. Pacific Command), considerably more pronounceable but changed probably because of possible confusion with the real Commander-in-Chief, the President of the US], but any further discussion of this matter belongs elsewhere in Wikipedia.
In my opinion it is also incorrect, and possibly confusing, to capitalize the initial letters of the words of this phrase in the introductory paragraph of this article: "...The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation.[1]...." The reason it is presented this way, I suspect, is an artifact caused by the writer's having copied the phrase as it is presented in the reference given, reference [1], in which the phrase is shown this way. But the only reason it is shown this way is surely merely because the phrase is part of the title of an article: "Gould, R. Gordon (1959). 'The LASER, Light Amplification by Stimulated Emission of Radiation'. In Franken, P.A. and Sands, R.H. (Eds.). The Ann Arbor Conference on Optical Pumping, the University of Michigan, 15 June through 18 June 1959. p. 128. OCLC 02460155." I, therefore, urge the writer to change to lower case those words of this phrase in the introductory paragraph now beginning with capital letters. Wikifan2744 ( talk) 07:51, 11 December 2013 (UTC)
I'm happy to see that the laser has been denoted as a significant technology, and I'm willing to invest effort in improving the article, but I'd like other editors thoughts on what key changes would help the article.
I feel the overall tone, and certainly the introduction, is tilted towards what makes the laser scientifically interesting rather than what makes it a valuable technology. I feel shifting that balance by providing a greater emphasis on applications and people's daily encounters with lasers would be beneficial.
Several of the current section feel like they would be better served by being distinct articles that were not trying to serve as broad an audience. Could the Laser Physics section be largely moved into laser science? How about limiting the discussion of laser types to one paragraph here and creating a separate article for anything more detailed than that?
To reconsider the overall structure of the article, I went searching for analogous topics that have an article with a higher rating. The three I found were steel, camera and telescope. I'm going to review these as potential guides. Do you have thoughts on other analogous articles?
Thanks for any thoughts and suggestions you can offer. I hope we can work together to raise the quality of this article. ronningt ( talk) 13:14, 8 December 2013 (UTC)
"It fundamentally changes the way we fight," said Capt. Mike Ziv, program manager for directed energy and electric weapon systems for the Naval Sea Systems Command.
"The Navy plans to deploy its first laser on a ship later this year, and it intends to test an electromagnetic rail gun prototype aboard a vessel within two years." — FYI, Charles Edwin Shipp ( talk) 15:23, 18 February 2014 (UTC) PS: There are some nice pictures.
More pictures, same AP story, February 17, 2014. FYI, Charles Edwin Shipp ( talk) 16:15, 18 February 2014 (UTC)
Really? 80.2.87.59 ( talk) 21:35, 19 March 2014 (UTC)
I am coming to laser optics from imaging with incoherent light and I'm trying to clarify a few things. First, I was surprised to learn that laser diodes spray light out over a wide angle—that they need a lens to produce a beam. This raises the question: is it their coherence that makes a laser diode well-suited to producing a beam or is it something about the area and angle over which light is emitted?
Specifically:
Thanks. —Ben FrantzDale ( talk) 03:16, 3 April 2014 (UTC)
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Please edit "A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation." so that when hovering above the word "laser" the full meaning should appear. This would be good for people viewing as the word is already bold and it provides an easier way to show the meaning of "laser" The following code can be used (the first is the original followed by the edited code: Original: A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Edited: A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. RahulSanthosh ( talk) 08:55, 19 May 2014 (UTC)
{{
edit semi-protected}}
template. I believe there is a current consensus in place against hovering definitions of words. I also believe there "may" be a userscript or gadget that will allow you to see some words like that. — {{U|
Technical 13}} (
t •
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c) 12:25, 19 May 2014 (UTC)This
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This article omits one of the most prominent and impactful applications of the laser - optical fiber communications.
At a BARE minimum, the 2nd paragraph should be edited from its current form:
Lasers have many important applications. They are used in common consumer devices such as optical disk drives, laser printers, and barcode scanners. They are used in medicine for laser surgery and various skin treatments, and in industry for cutting and welding materials. They are used in military and law enforcement devices for marking targets and measuring range and speed. Laser lighting displays use laser light as an entertainment medium. NASA has been experimenting with lasers for the purpose of transmitting data from space.[3] Lasers also have many important applications in scientific research.
to the following:
Lasers have many important applications. They are used in common consumer devices such as optical disk drives, laser printers, and barcode scanners. They are used in optical fiber communications to enable the internet. They are used in medicine for laser surgery and various skin treatments, and in industry for cutting and welding materials. They are used in military and law enforcement devices for marking targets and measuring range and speed. Laser lighting displays use laser light as an entertainment medium. NASA has been experimenting with lasers for the purpose of transmitting data from space.[3] Lasers also have many important applications in scientific research.
Optoeng ( talk) 21:50, 12 July 2014 (UTC)
Done Wow, yes. I'm not sure how we missed that. Thanks for pointing it out.-- Srleffler ( talk) 04:44, 14 July 2014 (UTC)
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I was taught in physics that it meant "linear amplification of spectral emission radiation" which is far more correct. When one examines the mode of operation this def'n is much more accurate. The gas is excited by a current causing an electron to raise to a higher orbital. When the field is collapsed the excited electrons all fall back simultaneously, giving off a photon at a characteristic wavelength, or spectrum. This is called "spectral emission radiation". The nature of the tube and window cause the linear amplification. Thank you 122.109.51.141 ( talk) 10:07, 23 July 2014 (UTC)
LASER is an acronym, why is the article name laser? 202.123.130.53 ( talk) 12:03, 25 August 2014 (UTC)
In the Semiconductor lasers section it's written:
Here is a good overview of commercially available wavelength that can be used as a reference.
This part
can be removed. These wavelength and particular diodes are listed in the reference above.
In general I would distinguish between laser diodes and diode lasers. This section is about laser diodes. External-cavity semiconductor lasers are diode lasers, i.e. systems. I would open a seperate section for diode lasers and write an article about diode lasers, unfortunately English is not my mother tongue. But is somebody know German, the respective article is here — Preceding unsigned comment added by 141.89.75.210 ( talk) 17:05, 26 September 2014 (UTC)
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85.189.149.201 ( talk) 08:44, 12 January 2015 (UTC) lasers are a bright light which can blind people and are banned in the uk and many other countries.
The usage and primary topic of laserlight is under discussion, see talk:LaserLight -- 65.94.43.89 ( talk) 10:16, 29 April 2015 (UTC)
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Please change
{{redirect|Laser light|the song|LaserLight}}
to
{{redirect|Laser light|the song|LaserLight|laser light show|laser lighting display}}
-- 65.94.43.89 ( talk) 10:22, 29 April 2015 (UTC)
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Experimentation in ultra violet laser technology has demonstrated the short burst potential of a laser can be reduced to attosecond length bursts.
Shirtbrigade ( talk) 12:43, 8 June 2015 (UTC)
Not done: as you have not cited reliable sources to back up your request, without which no information should be added to, or changed in, any article. - Arjayay ( talk) 13:01, 8 June 2015 (UTC)
Around the time of its invention, the laser was famously labelled 'a solution in need of a problem', but now it has penetrated so many aspects of industry, science and our daily lives that the number of applications are countless.
My emphasis. With a better source, that should become part of the history section. 85.178.192.101 ( talk) 13:16, 13 August 2015 (UTC)
I read something about a "monomode laser". Could someone define that term, please? Equinox ( talk) 13:46, 15 January 2016 (UTC)
See http://www.eng.umd.edu/html/ihof/inductees/weber.html for a summary of Joseph Weber's contributions to the development of the maser.
Added. EAWH ( talk) 02:28, 16 March 2016 (UTC)
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The title of the page is currently 'Laser' which is incorrect grammar for the topic presented. I request for a change of all words in/on page '(Laser -or- laser)' to be changed to 'LASER' due to the correct term being 'Light Amplification by Stimulated Emission of Radiation' Which is stated in the page on line 4 (line 3 if not including blank line) or the second sentence in the first paragraph. WTLM2013 ( talk) 14:20, 11 May 2016 (UTC)
Not done as policy mentioned above, and because, although derived from "Light Amplification by the Stimulated Emission of Radiation", as an acronym, laser is now a stand alone word in its own right.
You can find previous discussions about this further up on this page, and in the archives linked at the top of this page - the consensus is to stick with laser -
Arjayay (
talk) 15:47, 11 May 2016 (UTC)
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Perhaps someone could add to the first section that some lasers emit only one color of light because different colors will refract differently, and having a single wavelength keeps the beam narrow.
50.5.106.186 ( talk) 15:19, 11 August 2016 (UTC)
Not done Not a "complete and specific description of the request." Meters ( talk) 17:14, 11 August 2016 (UTC)
I've set "answered" to no because while the first section states that lasers emit a narrow spectrum, it is not clear to a person of mediocre intelligence that it allows the beam to stay narrow despite refraction.— Preceding unsigned comment added by 50.5.105.58 ( talk • contribs) 16:49, 9 October 2016 (UTC)
From the opening of the Gain medium and cavity subsection:
"Excited into an excited state?" Might as well say it was "purpled into a purpled state", or "frazzlerazzed into a frazzlerazzed state". The repetition is awkward, and fails to explain the meaning of "excited" in context.
Suggest replacing the sentence with "The gain medium is excited by an external source of energy", and then explaining what that means, or perhaps "The gain medium is placed in an excited state by an external energy source", again followed by an explanation of what "excited" means in this context.
Would have fixed it myself, but editing appears to be broken for this article. — Preceding unsigned comment added by 74.95.43.249 ( talk) 19:37, 27 October 2016 (UTC)
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The most important and biggest problem with building the first laser (and all and any lasers) was (is) that a two level system described in the Laser physics/Stimulated emission section could not amplify light because it can not attain population inversion; population inversion is a necessary contidion for a laser. Instead, a three level system needs to be used. The need for a three level system is crucial for understanding how a laser actually works and nowhere did I see it explained in the article. Someone who is better at writing/explaining than I am should add that in there. Details can be found, for example, in Svelto, Orazio (1998). Principles of Lasers. 4th ed. Trans. David Hanna. Springer. ISBN 0-306-45748-2. in the first chapter and in the chapter 1.3 especially about the necessity for a three level system. This book is cited as as a source in the article already. 93.142.7.8 ( talk) 10:57, 10 August 2017 (UTC)
I disagree with this edit and have partly reverted it. I would like to revert it completely, but am opening the issue up for discussion first.
The history is too important not to mention key points in the lede. The fact that Maiman was the first to build a working laser is not in dispute, and should be mentioned.
Gould is rightly considered the "inventor" of the laser, but only in the very narrow sense used in patent law, and that claim is tainted by the fact that he was (unjustly, in my opinion) denied the patent on the laser itself by the patent office. Gould does not deserve scientific credit for the theory of the laser, because he did not publish his work. Unlike the patent office, scientists credit the first to publish a discovery, not the first to think of the idea. The early scientific work on lasers is largely based on Schawlow and Townes' work, and they are conventionally credited with having originated the theory. I don't think there is any dispute that it is their theoretical work that led to Maiman's success in building the first laser, and their role is important enough that it should be mentioned in the lede.-- Srleffler ( talk) 07:48, 10 February 2018 (UTC)
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The term under consideration: In 2017, researchers from the Physikalisch-Technische Bundesanstalt (PTB), together with US researchers from JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, established a new world record by developing a laser with a linewidth of only 10 millihertz.[29]
In the cited article the authors describe that they have not used a gas laser, please see in [29]: "Commercial Er-doped distributed feedback (DFB) fiber lasers at 1542 nm (ν0=194.4THz) are frequency stabilized to the cavities using the Pound-Drever-Hall (PDH) method. Fiber-coupled acousto-optic modulators (AOMs) are used for the fast servo allowing locking bandwidths of around 150 kHz."
Recommended solution: Change the thematic classification to "Fiber lasers", which is now at "Gas Lasers".
Further information to the original term: Date: 10:32, 3 July 2017 Contributor: Bilingual2000 Topic: Gas lasers - added data and ref about the sharpest laser in the world with a linewidth of only 10 miliHertz) 141.24.58.195 ( talk) 13:09, 17 March 2018 (UTC)
Not done for now: I don't see the statement about Er-doped DFB lasers anywhere in reference 29. Reference 29 is The sharpest laser in the world. As far as I can see, it does not identify what the gain medium of the laser is. Where did you see that?-- Srleffler ( talk) 16:17, 18 March 2018 (UTC)
Partly done: I see now: your quote was from the Phys. Rev. Lett. paper, which is cited in reference 29. You are right—this is not a gas laser. I moved the paragraph to "Recent Innovations" rather than to "Fiber Lasers", though.-- Srleffler ( talk) 16:35, 18 March 2018 (UTC)
"Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond."
This formulation tends to let the reader to think that one needs a narrow spectrum to produce an ultrashort laser beam. It is actually the opposite due to Heisenberg uncertainty principle. To produce an ultrashort pulse (typically in the femtosecond range) one need a broad spectrum — Preceding unsigned comment added by MatthieuVe ( talk • contribs)
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Towards end of article, before sources section.
Lasers can be a hazard to both civil and miliatary aviation
'military' is spelled incorrectly. Tillmechanic ( talk) 17:13, 16 May 2019 (UTC)
@ Srleffler: per Wikipedia:Manual_of_Style/Pronunciation: For English words and names, pronunciation should normally be omitted for common words or when obvious from the spelling; use it only for foreign loanwords (coup d'etat), names with counterintuitive pronunciation (Leicester, Ralph Fiennes), or very unusual words (synecdoche)."
The pronunciation of laser is famously counterintuitive, and therefore should be included.
Onceinawhile ( talk) 19:10, 7 June 2020 (UTC)
I think that every article on Wikipedia should be written with encylopidic language. It'll be better if "LASER" redirected to "Light Amplification by Stimulated Emission of Radiation", not vice-versa, how it is now. BonsMans1 ( talk) 13:41, 26 October 2020 (UTC)
is laser light a tautology— Preceding unsigned comment added by 2601:2c3:4201:d70:5922:ac02:c737:d141 ( talk • contribs) 17:00, 28 November 2020 (UTC)
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Please change "1.3 PW (1.3×1015 W) – world's most powerful laser as of 1998, located at the Lawrence Livermore Laboratory[95]" to "10 PW - world's most powerful laser as of 2019, located at the ELI-NP facility in Măgurele, Ilfov, Romania. [1] [2]"
Gabi 2003RO ( talk) 16:29, 22 March 2021 (UTC)
References
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Please let me correct errors made by mindless editors. Phillotus ( talk) 23:18, 18 October 2021 (UTC)
I was surprised to see that the History section began with Einstein, making no mention of the original paper by Satyendra Nath Bose. Einstein's papers were founded in Bose's work, and in fact Einstein was instrumental in getting Bose's original paper published. Bose's paper was on the statistics of bosons, which was written at a time when the study of quantum statistics had developed a theory for fermions but not yet for bosons. Hs work was so important that bosons were named for him. Bose deserves mention. I'm adding a reference to his work.— MiguelMunoz ( talk) 08:30, 1 December 2021 (UTC)
Also, the article cites a 1917 paper by Einstein, On the Quantum Theory of Radiation from 1917, but I don't think that's right. The article on Bose claims his foundational paper was written in 1924, which was published with Einstein's help, in the same German journal as the 1917 paper. As I understand it, Bose's 1924 paper was the foundation of Boson statistics, which control the behavior of lasers. I'm going to look into this further. — MiguelMunoz ( talk) 08:54, 1 December 2021 (UTC)
The "Quantum vs. classical emission processes" section cites no sources. Please can someone add some helpful and trustworthy sources? Or at least add a "citations required" tag? Thanks. — Preceding unsigned comment added by 138.38.97.65 ( talk) 08:56, 6 February 2022 (UTC)
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I believe that a changes should be made in the section "Types and operating principles", subsection "Exotic media". Specificaly in the last paragraph, there is a description of a laser which uses living cells as an active medium. It is stated that "the mirrors were only 20 millionth of a meter apart". Such sensationalism has no place in a scientific article and it should definitely not be a part of Wikipedia. More natural would be to simply say 20 micrometers/microns. Also the author is using quotation marks relating terms like "gain medium" and "laser cavity". This is obsolete, these are standard terms that don't require quotation marks.
Sedlaon ( talk) 07:06, 11 April 2022 (UTC)
Done-- Srleffler ( talk) 03:21, 13 April 2022 (UTC)
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Dominics52 ( talk) 18:16, 15 April 2022 (UTC) I wanna see the sources of lasers
Can someone provide a better graph of the spectrum of a laser. The current one ( HeNe) is not very good for the following reasons: 1) The electronic background of the spectrometer is not subtracted so all the values that should be zero are currently quite wrongly shown, 2) the actual spectral distribution of the line is not shown - as the spectral width shown is clearly the band-pass function of the spectrometer and not the laser line-width. Thorseth ( talk) 10:00, 15 August 2022 (UTC)
Can someone please resolve the fact that every spelling of LASER in this article is incorrect? There's even a line stating LASER is an acronym and explains what it means but spells it in lower case. At least you didn't spell it with a Z. 92.1.183.81 ( talk) 19:50, 1 September 2022 (UTC)
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The first laser, it was called a maser, was made in 1953 – 1954 by N.G. Basov and A.M. Prokhorov. In 1964, Basov and Prokhorov received the Nobel Prize in Physics.
https://ru.m.wikipedia.org/wiki/%D0%91%D0%B0%D1%81%D0%BE%D0%B2,_%D0%9D%D0%B8%D0%BA%D0%BE%D0%BB%D0%B0%D0%B9_%D0%93%D0%B5%D0%BD%D0%BD%D0%B0%D0%B4%D0%B8%D0%B5%D0%B2%D0%B8%D1%87 2A00:1FA1:4231:F126:2C9:BC40:D9D5:252D ( talk) 08:35, 2 September 2022 (UTC)
As the article states, this is an acronym. It is spelled "LASER". 79.106.209.51 ( talk) 23:43, 29 December 2022 (UTC)
Seems odd, and strange, to me that the verbage of the article calls lasers “they” as if it’s a living being.
Didn’t find much info on laser light shows that aren’t raves, either.
2600:8801:0:2B10:1C4B:8BDE:2599:1884 ( talk) 14:26, 17 January 2023 (UTC)
The history section claims that Javan was the first to propose the semiconductor laser. Not only had others proposed it before him in some capacity (Jun-ichi Nishizawa, for example, who is actually mentioned earlier in that same section), but this claim is not cited, or flagged as needing citation. I have looked extensively for a source to back up this claim, but can find nothing. This seems to be, at best, original research, and at worst, a fabrication. This error should probably be amended.
(G!d bless Ali Javan by the way, huge inspiration to me) ProteinFromTheSea ( talk) 23:58, 30 May 2023 (UTC)
As expressed in the notes left to some (laser) physics-specialised users, I am planning on making the level-3 vital article "Laser" a GA. Two persons responded to these notes —one directly and one indirectly by editing the article to some extent—, and I think now is the time for me to start intervening more energetically.
Having taken the six GA criteria into consideration, I list my intentions/suggestions below:
1.a. & 1.b. Language style homogenisation; I'm planning on reading the whole article and making sure the text is technically and stylistically consistent. At the same time, I'll ensure Manual of Style compliance.
2. a. I know it shan't be easy, but I shall try to turn all citations to
Harvard referencing, for I find it more easy to handle, more "tidy" (cancelled, see below).
2.b. & 2.c. I will try to find citations for all text requiring substantiation.
2.d. Using Earwig's Copyvio etc, I'll check for possible copyright violations.
3. I do not think much vitally important information is missing from the article, but if I find any omissions, I'll fix them.
4. The article is probably neutral, but I'll make it more so, if possible.
6. Some important pictures are missing; for example, a photo of the late Mr. Maiman ought to be included.
Let's get to work, then! Whoever willing to help is invited to do so.
P.S. Bear in mind that some of my extensive edits might significantly change the article's appearance and structure over a short period of time, so it would be more convenient if you informed me of any intended extensive change beforehand, here, at the article's talk page. L'Orfeo Son io 11:40, 15 October 2023 (UTC)